Psychometrics is a field of study concerned with the theory and technique of psychological measurement. One part of the field is concerned with the objective measurement of skills and knowledge, abilities, attitudes, personality traits, and educational achievement.Human interactions: relationships, feelings, attitudes, loyalties, perceptions and engagements do not yield easily to numeric quantification.======================L.L. Thurstone. 1959. The Measurement of Values. Chicago & London: The University of Chicago Press